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Need to change a Gen4 454 from reverse to standard rotation

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Whttnbrg

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I have a 1987 reverse 454, i also have a zf 63a I need to reverse the motor to use the gear. I have been told three different things and I don't know what to believe.

1. With the motor being a 1987, all I need to do is change the timing from the gear set to the chain.

2. I need to change the timing, cam, and lifters.

3. I need to change the crank and everything above.

Is there anyone that can tell me what I need to do. My brother is a mechanic, and will help me do the
work, I just want to make sure I do it right.

thanks for the help
 
Whttnbrg, you will find people that do not understand how to determine Engine Rotation... so just that we're both on the same page here:

The Standard LH rotation engine will turn CCW when viewed from the flywheel end..... same as all car and truck engines.
Conversely, the Reverse RH rotation engine will turn CW when viewed from the flywheel end.

Here is how your Rev RH engine will rotate, as shown turning Clockwise.
images

This is just oposite from Car/Truck rotation and is the industry standard means of determining engine rotation.



Whttnbrg said:
I have a 1987 reverse 454, i also have a zf 63a I need to reverse the motor to use the gear. I have been told three different things and I don't know what to believe.

1. With the motor being a 1987, all I need to do is change the timing from the gear set to the chain.

2. I need to change the timing, cam, and lifters.

3. I need to change the crank and everything above.

Is there anyone that can tell me what I need to do. My brother is a mechanic, and will help me do the
work, I just want to make sure I do it right.
Click to expand...
You are receiving some incorrect advice!

1. No... that is incorrect!
The Rev RH rotation camshaft cannot be re-used for the Standard LH rotation engine because the Intake valve initial operation occurs first, with the Exhaust valve ending operation occuring last (within the four cycles).
Cam indexing, over-lap, duration, etc, etc, just won't allow for this.

Also..... camshaft indexing and profiles vary depending on which drive system....
I.E., sprockets and chain drive -vs- twin gear drive -vs- 4 gear drives, etc, for examples.


2. Yes on the camshaft and new cam follows. New cam follows are necessary for a new camshaft unless roller cam/followers.

3. Incorrect regarding the crankshaft. Crankshaft is the same..... we're simply rotating it oposite.
The wrist pin offset will require being changed.


Chris, correct me if I'm wrong here..... but he won't want to flip the connecting rods around since they will be numbered and must face the correct direction within the crank journal. The wrist pin offset is addressed by changing the piston orientation on the connecting rod.


Whttnbrg, imagine this being a Port side cylinder head that has been tilted up to expose #1, #3, #5 and #7 cylinders.
The valves are arranged from #1 to #7 cylinder; Exhaust/Intake, Exhaust/Intake, Exhaust/Intake, Exhaust/Intake.
The valve reliefs in the #1, #3, #5 and #7 pistons reflect and follow the valve configuration.

174X-Deck-small.jpg


A good machine shop person can change the piston/rod orientation........ but I doubt that you'd tear into this without replacing pistons.


Crankshaft main seals differ from Standard LH rotation to Reverse RH rotation by a change to the tiny serrations at the seal lip.
These wipe the oil differently from LH to RH rotation.

Distributor and oil pump will always rotate standard (CW when viewed from overhead).
The cam and distributor "drive" and "driven" gear cuts maintain this rotation.
IOW, there is no REV oil pump.
However, there will be a difference in the up/down thrust load within the distributor.

Ignition timing and indexing is oposite from Standard LH ignition indexing, begining with #1 cylinder.
The Std. LH rotation firing order is 1-8-4-3-6-5-7-2 ..... the Rev RH engine firing order will be 1-2-7-5-6-3-4-8.


bbc-firing-order.jpg


Question: typically a Rev RH engine is worth a bit more than a standard LH rotation engine. Why not sell the running Reverse RH rotation engine, and build or buy yourself a Standard LH engine?


.
 
Last edited:
I have looked at selling it. No body wants it. Everybody counter rotates with the transmission now. I got it at a great price too, and it has almost no hours on it. I just wasn't completely aware of what was going on. It came with a velvet drive that reversed the output, but it it really long, and I need the down angle of the ZF. It is a complete marine drop in. I would love to trade it for a complete standard, if there was one close to Louisiana. I can get the parts for around 300, to switch it. My main concern is will it be worth it, and will it work. I have been told the motor doesn't know or care what direction it rotates.
 
Whttnbrg said:
1.... I can get the parts for around 300, to switch it.

2.... I have been told the motor doesn't know or care what direction it rotates.
Click to expand...
1... I'm not sure what you're asking here regarding a $300 budget.
Are you proposing that the low hour pistons will change bores and will be re-used?

2... True, certain components will not care which direction they are rotated. Crankshaft, rods, even pistons when the wrist pin offset has been corrected.

Camshaft will definitely require changing.
If sprocket and chain drive now..... and if in good condition, these could be re-used.
Roller cam followers could also be re-used when you consider how long these will run. However, there are factors that must be considered. Roller diameter, for an example. This must work with the cam profile. Your camshaft supplier will suggest whether this is OK or not.

Don't forget about the starter motor!

.
 
Something that doesn't make sense to me with your last statement. You said it came with a Velvet drive tranmission that reversed the direction.

The reason they had Reverse rotation engines, back then, was because the transmission would not run it in reverse. (Cept Volvo..another story)
So think about your statement. "I have a reverse rotation engine with a reverse rotation transmission! That makes it all run....standard rotation"??

Sounds like you may have a reverse rotation engine, but not the tranny. (Straight through) I have a 88 model setup with twins out in my yard. Both Velvet drive Borg Warners. 1 with std rotation, the other with a Reverse rotation.

If it were me, I would absolutley verify, (with that Ricardo-dudes drawing) that you have a Reverse roation engine. It does get confusing.
 
By-the-way, In the 90's, the transmission mfg's. got their s&*t together and figured out how to make their tranny's run backwards, so we don't have this reverse rotation engine problem.
 
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